Do you need BDD style of system tests ?

BDD was largely introduced as a bridge between domain experts who are usually not technical users and Engineers who are supposedly no domain experts. BDD gives an ability to domain experts to describe application feature in Given, When, Then style and these are then turned in to real application feature by Engineers. All stakeholders have common reference of understanding.

But it does not stop there, there was great value (and probably there is ) seen in writing system tests which follow BDD style. JBehave, Cucumber-JVM come on mind quickly. These APIs also help bridge the gap between technical and not technical user, but the questions we need to ask is -

• Would you be able to get product specialist write the feature files? If not then you would have two sources of information one written by product specialist (probably in JIRA or another tool) and another feature file written by developer or test engineer

• Will product specialists ever execute the test?
• Do you want to introduce an extra layer of steps when you might be the only one working and verifying the tests?

BDD Scenario from Dan North  - 

+Scenario 1: Account is in credit+
Given the account is in credit
And the card is valid
And the dispenser contains cash
When the customer requests cash
Then ensure the account is debited
And ensure cash is dispensed
And ensure the card is returned

Modification from James Basch -

+Scenario 1: Account is in credit+
Given the account is in credit
And the card is valid
And the dispenser contains cash
When the customer requests cash
Then check that the account is debited
And check that cash is dispensed
And check that the card is returned
And check that nothing happens that should n’t happen and everything else happens that should happen for all variations of this scenario and all possible states of the ATM and all possible states of the customer’s account and all possible states of the rest of the database and all possible states of the system as a whole, and anything happening in the cloud that should not matter but might matter.

Source

• Are you ready to deal with the complexity of information flow when you have to maintain the state from step to step ?

And how do you solve the communication problem if you don't use cucumber? Talk to your stack holders, no amount tools can replace face to face communication. BDD is no guarantee of not doing things wrong and decision is yours.

When I was writing cucumber tests then they became source of truth for manual testing team to assume application works well and in case test fail I would have to fix them. I am not sure if cucumber solves any problem when used in this manner.